1. Field of the Invention
The present invention relates to a catheter having an inflatable balloon at one of its ends for retaining the catheter within a patient's body. More particularly, the present invention relates to a balloon catheter wherein the catheter tube has a port adjacent its distal end, and the inflatable balloon has an opening aligned with the port and is secured to the tube such that the adjacent peripheries of the port and opening are adhered together to provide an inflated cushion completely about the port and the tube distal end and a tapered lead in for the port.
2. Description of the Prior Art
Catheters comprising an elongated flexible tube with an inflatable balloon attached to the tube at its distal end are often used to drain urine from a patient's bladder. The distal end of the catheter is inserted through the urethra and positioned such that the drainage ports and the inflatable balloon are inside the bladder and its proximal end is outside the patient's body. The balloon is then inflated to secure the catheter distal end in the bladder. The drainage ports are in fluid communication with a drainage lumen extending in the tube to permit urine to drain from the bladder and into a container coupled to the catheter proximal end.
A variety of balloon arrangements have been employed in conventional catheters. Typical examples are disclosed in U.S. Pat. Nos. 4,022,216, Stevens; 3,438,375, Ericson; 3,954,110, Hutchison; and 4,157,094, Patel.
The Stevens patent discloses a catheter having two inflatable balloons located on opposite sides of oblong inlet openings in the catheter tube. Each balloon is supplied with an inflating fluid through separate passageways. The balloons are secured to the catheter tube at locations spaced from the edges of the inlet openings in the tube.
The Ericson patent discloses a variety of balloon catheter configurations. In FIGS. 1-17, a single balloon is located within the tube inlet opening located on the side or open upper end of the catheter tube such that upon inflation, the tube extends around only a portion of the tube inlet opening. In FIGS. 18 and 19, the balloon is attached to the catheter tube at locations adjacent to, but spaced from, a single catheter tube inlet opening. In FIGS. 20-21, the balloon is spiral in shape and covers inlet openings in the catheter tube.
The Hutchison patent discloses a catheter with a balloon which is attached to the end of a catheter tube, but which only surrounds the upper and lateral edges of the inlet openings in the catheter tube. The extreme distal ends of the balloon and tube are cemented together so that the tip is not cushioned upon inflation of the balloon.
The Patel patent discloses another conventional balloon shape which is located only below the inlet opening in the tube. In this catheter, the tip is formed from a separate member from the tube and is secured thereto by means of an adhesive.
These devices suffer from numerous disadvantages. For example, the two balloons of the Stevens patent which are spaced from the ports in the tube do not cushion the tube, provide a tapered inlet, prevent organ tissue from being suctioned into the tube and drain the organ adequately. In a similar manner, the Ericson, Hutchison and Patel patents do not provide sufficient protection from the reinforced tip of the tube and/or do not have balloons which completely surround the tube inlet opening to protect the tissue adjacent to the opening and to facilitate drainage.
Furthermore, these conventional catheters are relatively complex in arrangement and are difficult and expensive to manufacture.